1. Field of the Invention
The present invention relates to a terminal connecting device which ensures ease and efficiency in performing electrical or other connection operations.
2. Description of the Background Art
To facilitate understanding of the present invention, conventional type terminal connectors will be described below with reference to FIGS. 9-11.
FIG. 9 is a sectional plan view of a part of a conventional terminal connector disclosed in Japanese Unexamined Utility Model Publication No. 50-5160. FIG. 10 is a sectional front view of a part of the terminal connector shown in FIG. 9.
It should be noted that FIG. 9 is a sectional view of the terminal connector taken along line 9--9 in FIG. 10, and FIG. 10 is a sectional view of the terminal connector taken along line 10--10 in FIG. 9.
In FIGS. 9 and 10, reference numeral 801 designates a case for an apparatus on which the terminal connector is mounted while reference numeral 802 designates a meandering or snake-like spring of which opposite ends are supported by the case 801. Reference numeral 803 designates a terminal screw which is supported by the spring 802 at a central part thereof so as to be displaceable in the vertical direction as shown in FIG. 10. It should be noted that the terminal screw 803 is illustrated as divided, at an intermediate position, between a head portion and a male-threaded portion 803a. Reference numeral 804 designate a wire retainer for holding the object to be connected, reference numeral 805 designates a stationary terminal having a female-threaded hold 805a formed thereon, and reference numeral 806 designates a leaf spring which is received in an annular groove 801a for urging the stationary terminal 805 vertically upward.
A process for fastening and connecting a round type crimp terminal to the conventional terminal connector, as shown in FIGS. 9 and 10, is described hereinafter.
First, to ensure that the terminal screw 803 is inserted through a hole of the round type crimp terminal, the terminal screw 803 is loosened so that it is disengaged from the stationary terminal 805.
With the terminal screw 803 in a disengaged state, a gap is created between the male-threaded portion 803a and the stationary terminal 805, the gap being wider than at least one plate thickness of the stationary terminal 805.
Next, the round type crimp terminal is inserted into the terminal connector such that a hole of the round type crimp terminal is aligned with and located at a position between the male-threaded portion 803a of the terminal screw 803 and the female-threaded hole 805a of the stationary terminal 805.
Subsequently, when the terminal screw 803 is rotationally displaced vertically downward with the aid of a thread tightening tool (e.g., a screwdriver) so that it is threadably engaged with the female-threaded hold 805a of the stationary terminal 805, the round type crimp terminal is immovably fastened and connected to the stationary terminal 805.
FIG. 11 is a sectional front view of a part of another conventional terminal connector as disclosed in Japanese Unexamined Utility Model Publication No. 59-177176.
In FIG. 11, reference numeral 1001 designates a case for an apparatus on which the terminal connector is mounted, reference numeral 1002 designates a stationary terminal which is fixedly secured to the case 1001, reference numeral 1003 designates a coil spring, of which the upper end is held on the case 1001 and the lower end is suspended toward a female-threaded hold 1002a of the stationary terminal 1002, and reference numeral 1004 designates a terminal screw.
It should be noted that the terminal screw 1004 includes a spring washer 1006 and a washer 1007 each being undetachably interposed between a head portion 1004a and a male-threaded portion 1004b.
The lower end of the coil spring 1003 is fitted over an annular recess 1004c formed concentrically about the head portion 1004a of the terminal screw 1004 such that the male-threaded portion 1004b of the terminal screw 1004 is suspended toward the female-threaded hole 1002a of the stationary terminal 1002.
A process for connecting a round type crimp terminal to the conventional terminal connector, as shown in FIG. 11, is described hereinafter.
As shown in FIG. 11, when the terminal screw 1004 is disengaged from the stationary terminal 1002, the male-threaded portion 1004b of the terminal screw 1004 is suspended in spaced relationship relative to the stationary terminal 1002 by a distance greater than at least one plate thickness of the round type crimp terminal.
Next, the round type crimp terminal is inserted into the region located between the male-threaded portion 1004b of the terminal screw 1004 and the stationary terminal 1002 such that a hole of the round type crimp terminal positionally coincides with the female-threaded hole 1002a of the stationary terminal 1002.
As the terminal screw 1004 is displaced downwardly against the contracting force of the coil spring 1003, to be threadably fitted into the female-threaded hole 1002a of the stationary terminal 1002, the round type crimp terminal is fastened and connected to the stationary terminal 1002.
Where an open end type crimp terminal is to be fastened and connected to the conventional terminal connector, as shown in FIGS. 9 and 10, the terminal screw 803 is only slightly threaded into the female-threaded hold 805a of the stationary terminal 805, the open end type crimp terminal is inserted in the hollow space between the wire retainer 804 and the stationary terminal 805, and the terminal screw 803 is then displaced further in the downward direction so that it is secured to the stationary terminal 805.
Where one end of a cable, e.g., a naked wire, is to be connected, the terminal screw 803 is slightly threaded into the female-threaded hole 805a of the stationary terminal 805 in the same manner as described above. Then, while the foregoing threadably engaged state is maintained, the naked wire is inserted into the hollow space between the wire retainer 804 and the stationary terminal 805, and the terminal screw 803 is then displaced further in the downward direction until the naked wire is immovably secured to the stationary terminal 805.
When an open end type crimp terminal or a naked wire is to be immovably fastened and connected to the conventional terminal connector, as shown in FIG. 11, it can be fastened and connected in the same manner as described above with respect to the conventional terminal connector shown in FIGS. 9 and 10.
With the conventional terminal connector, as shown in FIGS. 9 and 10, the male-threaded portion 803a of the terminal screw 803 is typically difficult to position so as to coincide with the female-threaded hole 805a of the stationary terminal 805 as the terminal screw 803 and spring 802 are displaced downwardly toward the female-threaded hole 805a of the stationary terminal 805. In such a case, the terminal screw 803 must be displaced, by hand, in the horizontal (left or right) direction until the male-threaded part 803a of the terminal screw 803 positionally coincides with the female-threaded hole 805a of the stationary terminal 805. Thus, with the conventional apparatus, it is extremely difficult to achieve the proper alignment for fastening.
Furthermore, the conventional terminal connector, as shown in FIG. 11, suffers from the same problems as noted above with respect to the conventional terminal connector shown in FIGS. 9 and 10.